Among the known methods of human contraception, is the one that consists in placing a contraceptive device inside the uterine cavity.
Many variations exist relating to the problem of maintaining the contraceptive device in place without causing any injury or embarrassment.
But the contraceptives known up to date are most often adapted to the uterus of a woman, the shape and dimensions of which are such that the device for maintaining in place the contraceptive is always supported on the intrauterine walls.
Up until now it has not been possible to utilize the known contraceptive principles used by women to apply them, by somewhat adapting them as need be, to animal species when it is desired to control birth only for those species having a uterus of the same type as that of a woman. For other species, this adaptation has been impossible, especially for canine and horse species.
In fact, the genital system of those species is quite different from that of a woman and no simple transposition has proven satisfactory.
That is the reason until now one had to be content with using less than effective methods such as the foams, oral hormonal contraceptives or injectable hormonal contraceptives, either radical, dangerous and burdensome such as ovariectomy (removal of ovaries) or tieing of uterine tubes.
It would be of the greatest interest for animal owners as well as for the animals themselves to be able to use a contraceptive because, as is known, it is a simple and not burdensome method, perfectly reversible (removal of the contraceptive is very easy in case of a wanted pregnancy), having no disadvantage concerning the health or behavior of the subject and, finally, being completely reliable.
To demonstrate the state of the art, one must note, especially, U.S. Pat. No. 3,507,274 which describes a contraceptive having divergent arms, the exterior faces 28 of which of the developed parts 24 must be in contact with the walls 29 of the interior 30 of the uterine cavity A, under the channels or openings D of the tubes (page 1, column 2, lines 55 to 59).
Also known is Great Britain Pat. No. A-2,079,158 relating to a contraceptive for females of certain animal species, but it contains no teaching relating to maintaining the contraceptive in place by the uterine prongs and, on the contrary, describes the placing of the contraceptive inside the uterine cavity itself, the whole contraceptive having sufficient elasticity to permit folding of its lobes (and not the arm) and their natural elastic unfolding (page 2, lines 31 to 37).
French patent No. A-78/16.160 also describes a contraceptive, the arms of which must be supported against the wall of the uterus as is specified page 1, line 17 and lines 19 to 22. The contraceptive according to the invention is intended for certain animal species and could not be used by women whose uterus is not provided with Y-shaped channels while the contraceptive described in this patent is usable only in medicine (and not in veterinary art), as the result of indications such as the words: "medicine" page 1, line 2, "comfort of the patient" page 1, line 10, "physician" page 2, line 27, etc.
Moreover, it is clearly established that this contraceptive does not have divergent arms beyond the top of the stem.
On the contrary, the present invention permits the making of a contraceptive intended for females of animal species whose uterine cavity is different from that of the human species, and this is the case, more particularly, of bitches.
A contraceptive according to the invention is of the type comprising a central stem and a device for maintaining in place the said stem at the interior of the uterine cavity of a subject, said device being composed of two elastic arms which are symmetrical in relation to the stem integrally therewith at its top, and which naturally occupy a position in which they diverge beyond the top of the stem by making an angle between each other, characterized in that the top of the stem must be located in the neighborhood of the bottom of the uterine cavity, the arms must be placed beyond this cavity, in two uterine Y-shaped channels which the uterus of females of a given animal species has, and more particularly the canine species, the angle of the arms being greater than that which the said uterine Y-shaped channels make between each other.
According to other characteristics of the invention:
the arms bear on their extremity exterior outlines having a nonwounding bent surface and, preferably, giving to the extremity of each arm a half-ovoid shape; PA1 the contraceptive in fact is a synthetic material, such as polyethylene, containing particles of dispersed copper; PA1 the contraceptive is made of a synthetic material, such as polyethylene, containing at least a metallic salt such as barium sulfate.
The invention will be better understood by the following detailed description made by referring to the attached drawing. Of course, the description and the drawing are given only as an example and not as limitation.